Conventional regeneration processes for catalysts with a reduced catalytic activity typically include removal of coke deposits from the catalyst surface. Treating catalysts to remove coke typically includes contacting such catalysts with air or another oxygen-containing gas at high temperatures (e.g. at least ≥450 degrees Celsius (° C.) for an ethanol dehydrogenation catalyst and ≥650° C. for a fluid catalyst cracking (FCC) catalyst)). Depending on the type of catalyst, additional treatment may be necessary, such as, re-dispersion and reduction (in the case of platinum-tin based dehydrogenation catalysts) and reduction alone in the case of palladium based acetylene removal catalysts. When applied to gallium-based alkane dehydrogenation catalysts, the conventional catalyst regeneration processes do not, however, fully restore or even substantially fully restore catalytic activity of gallium-based dehydrogenation catalysts to a level equaling or even approaching that of fresh, unused dehydrogenation catalysts. Those who practice alkane dehydrogenation, especially propane dehydrogenation (PDH), understand that as activity of a catalyst decreases, alkene production also decreases with a negative impact on the process economics.
For gallium-based catalysts, one approach to restoring the activity of alkane dehydrogenation catalysts is to include an air-soak step after the coke combustion step in the presence of additional fuel (Ref. WO 2013/009820). Deactivated gallium-based alkane dehydrogenation catalysts, however, require a prolonged air-soak treatment during its regeneration to restore and sustain activity cycle to cycle. Longer air-soak times translate to larger catalyst inventory and larger regenerator equipment impacting capital and operating cost of the alkane dehydrogenation process. Reducing the required air-soak time would help to improve the alkane dehydrogenation process performance and economics.